<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>成绩判断</title>
</head>
<body>
  <script>
    //输入成绩
    let score = +prompt('请输入成绩:')
    if(score >= 90){
      alert('宝贝，你是我的骄傲!')
    } else if(score >= 70){
      alert('还不错,继续努力!')
    } else if(score >= 60){
      alert('你很危险哟!')
    } else {
      alert('宝贝,看来我们需要做一道竹条炒肉片菜了!')
    }
  </script>
</body>
</html>